This invention relates to the use of low calorie or no calorie fat mimetics in total or partial replacement of the highly caloric triglyceride fats and oils normally found in edible compositions.
Dietary fat is the most concentrated source of energy of all the nutrients, supplying 9 kcal/gram, about double that contributed by either carbohydrate or protein. Compared to minerals, such as calcium carbonate, the normal dietary fat is more often associated with negative health implications. The amount of fat in the American diet has increased in the last 60 years by about 25% (Mead, J., et al. Lipids, Plenum, New York, 1986, page 459), so that fats now provide approximately 40% (or more) of the daily caloric intake.
Because fats are high in calories and because some fats have been associated with health risks when consumed in large quantities over time, a number of national advisory committees on nutrition have recommended that the total amount of fat in the diet be reduced significantly (Gottenbos, J. J., chapter 8 in Beare-Rogers, J., ed., Dietary Fat Requirements in Health and Development, A.O.C.S. 1988, page 109).
Fat is not, however, without health and nutrition benefits unique to itself, and it would be desirable to retain these. Fat contributes to the palatability and flavor of food, since most food flavors are fat-soluble, and to the satiety value, since fatty foods remain in the stomach for longer periods of time than do foods containing protein and carbohydrate. Furthermore, fat is a carrier of the fat-soluble vitamins, A, D, E, and K, and the essential fatty acids, which have been shown to be important in growth and in the maintenance of many body functions. It would be desirable to provide a way to produce food substances that provide the nutritional, as well as functional and organoleptic benefits of fats while greatly reducing the calories. It would be further desirable to provide a fat mimetic of this type which would be of a nature which could be injested in sufficiently large quantities to make it possible for consumers to significantly reduce their total fat intake.
The most abundant group of fats are esters of fatty acids with the trihydroxy alcohol, glycerol. Early studies reported that fats having high melting points were less digestible (Deuel, H. J., The Lipids, vol. II, Interscience Publishers, 1955, pages 218 to 220). Later investigators questioned the relationship between digestibility and melting points, and scrutinized instead the chain lengths and degree of unsaturation of fatty acid substituents; (Carroll, K. K., J. Nutr. 64: 399-410 (1957) at 408). (Hashim, S. A., and Babayan, V. K., Am. J. Clin. Nutr. 31: S273-276 (1978)).
Triglycerides having stearic acid in combination with medium chain substituents have been suggested as low calorie fats (European Published Pat. App. No. 322,027 to Seiden). Low calorie triglyceride mixtures having stearic acid at the 1-position and medium and unsaturated residues in the other positions have also been suggested (U.S. Pat. No. 4,832,975 to Yang).
Unfortunately, these fats, even if effective in reducing calories, are not known to reduce the total fat intake. And, triglycerides high in stearic acid tend to be high melting. The production of these tailored triglycerides can also be difficult for several reasons including the tendency of some processes to produce large amounts of tristearin, the melting point of which is so high that it causes a waxy mouthfeel if used in amounts of even two percent in products like margarine. Tristearin is a solid at room temperature; the alpha form is a white powder that melts at 55.degree. C., which, on solidification, reverts to the beta form that melts again at 72.degree. C.
The quest for low calorie fats has largely been to structurally re-engineer triglycerides. The goal has been to retain their conventional functional properties in foods, while reducing their susceptibility toward hydrolysis or subsequent absorption during digestion. To this end, the glycerol moiety been replaced with alternate polyols (e.g., pentaerythritol in U.S. Pat. No. 2,962,419 to Minich, or sugars in U.S. Pat. No. 3,600,186 to Mattson and Volpenhein and U.S. Pat. No. 4,840,815 to Meyer, et al.); the fatty acids have been replaced with alternate acids (e.g., branched acids as described in U.S. Pat. No. 3,579,548 to Whyte); groups have been inserted between the glycerol and the fatty acids (e.g., ethoxy or propoxy groups in U.S. Pat. No. 4,861,613 to White and Pollard); the ester bonds have been reversed (e.g., malonates in U.S. Pat. No. 4,482,927 to Fulcher and trialkoxytricarballylates in U.S. Pat. No. 4,508,746 to Hamm); and the ester bonds have been replaced by ether bonds (Canadian Pat. No. 1,106,681 to Trost).
More radical departures from restructured triglycerides employ materials developed from unrelated chemistry. Mineral oil was suggested as an edible fat replacement as early as 1894 (U.S. Pat. No. 519,980 to Winter), and numerous other compounds, including polymers such as polyglucose and polymaltose (U.S. Pat. No. 3,876,794 to Rennhard), polyoxyalkylene esters (U.S. Pat. No. 4,849,242 to Kershner), and polyvinyl alcohol esters (U.S. Pat. No. 4,915,974 to D'Amelia and Jacklin), have been considered. (For recent reviews, see Hamm, D. J., J. Food Sci. 49: 419-428 (1984), Haumann, B. J., J. Amer. Oil Chem. Soc. 63: 278-288 (1986) and LaBarge, R. G., Food Tech. 42: 84-90 (1988).)
Nondigestible or nonabsorbable fat replacements have proved disappointing when tested in feeding trials, where gastrointestinal side effects occurred, in some cases so extreme that frank anal leakage was observed. Nondigestible fats appear to act as a laxative and are expelled from the body, eliciting foreign body reactions like those early documented for mineral oil (Stryker, W. A., Arch. Path. 31: 670-692 (1941), more recently summarized in Goodman and Gilman's Pharmacological Basis of Therapeutics, 7th ed., Macmillan Pub. Co., N.Y. 1985, pp. 1002-1003). In the U.S.D.A.'s assessment of the caloric availability and digestibility of a series of new-type fats in the 1960's (e.g., amylose fatty acid esters, diglyceride esters of succinic, fumaric, and adipic acids, and polymeric fats from stearic, oleic and short-chain dibasic acids; see Booth, A. N., and Gros, A. T., J. Amer. Oil Chem. Soc. 40: 551-553 (1963) and the references cited therein), rats fed the experimental fats exhibited undesirable gastrointestinal side effects similar to what had already been observed with mineral oil consumption by people. In several of the balance studies, the diarrhea was so extreme that digestibility coefficients could not be calculated (ibid., Table I, p. 552).
The laxative side effect has shown to be so pronounced that it still persists for liquid sucrose polyesters even after blending them with a fiber such as microfibrillated cellulose or a fully hydrogenated sucrose polyester of soybean oil fatty acids. (European Pat. App. 352,907 to Howard and Kleinschmidt) Even in the case of plastic sucrose polyesters, the use of cellulose is used by these researchers at seven percent. That disclosure further noted that cellulose of this type is known for use in reduced-calorie foods including jellies and spreads and as thickeners, flavor carriers or suspension stabilizers in other foods. The use of cellulose either alone or with sucrose polyesters, adds food weight without adding food value. Indeed, the combination could, if precautions are not taken, remove vitamins, minerals and essential fatty acids from the diet. What is desired is a reduced-calorie fat substitute which is more in line with traditional nutrition rationale and is free of novel nutritional interactions which may not be fully understood and could affect the normal cascade of biochemistry.
Among other attempts to reduce calories by adding nutritionally inert additives is the disclosure of Yokoyama, Fraser and Khatri in U.S. Pat. No. 4,619,705 which asserts that polydextrose and/or microcrystalline cellulose can be employed to advantage in formulating a spread similar to peanut butter. The use of high-surface-area, small particles of microcrystalline cellulose is said to bind oil too tightly and particle sizes are kept to above 5 microns. Polydextrose is disclosed as effective because its density and smooth surface characteristics reportedly absorb or immobilize little oil. When polydextrose is employed it is sometimes desired to add a base such as calcium or magnesium hydroxides, oxides or carbonates. These additives, however, are not fat mimetics because they are not used as the sole fatty component in a food--solely as fillers for an existing fat. It would be more desirable to have a material which was effective not only as a filler material, but which could function also as a true substitute for natural fats. In European Pat. App. No. 380,225, Hendrick and Reimer disclose coating a core material with a digestible fat. It would, however, be desirable to enable the use of mineral cores which could provide nutrition as well as increased economy.
In U.S. Pat. No. 4,865,850, Shell and See disclose the administration of fat absorbing particles to remove fat from the gastrointestinal tract. The particles comprise a non-biodegradable material such as cross-linked collagen coated with a fat receptive material such as bile and have diameters of from 2 to 50 microns. This material is not, however, a fat substitute. It is a non-nutritional fat scavenger.
A number of other remedies have been recommended to combat the anal leakage observed when sucrose polyesters are ingested (e.g., employing cocoa butters, U.S. Pat. No. 4,005,195 to Jandacek, incorporating saturated fatty groups, Eur. Pat. App. No. 233,856 to Bernhardt, or mixing residues, U.S. Pat. No. 4,797,300 to Jandacek, et al.), and dietary fiber preparations have been incorporated into polysaccharide and/or polyol-containing foodstuffs to help inhibit the diarrheal effect (U.S. Pat. No. 4,304,768 to Staub et al.).
The sucrose polyesters and other non-digestible fat substitutes tend to have a stool softening effect despite taking precautions. Polyglycerol and polyglycerol esters, suggested as fat replacements by Babayan and Lehman (U.S. Pat. No. 3,637,774), have been suggested for use as fecal softening agents as well (U.S. Pat. No. 3,495,010 to Fossel). It would be desirable to have fat substitutes which do not cause anal leakage or stool softening. Partially digestible fat replacements have also been suggested as a better approach to avoid or diminish the known problems associated with nondigestible and non-nutritious fat substitutes. ( U.S. Pat. No. 4,830,787 to Klemann and Finley; U.S. Pat. No. 4,849,242, cited above; and U.S. Pat. No. 4,927,659 to Klemann, et al.).
In another approach to fat replacements, Singer, Yamamoto and Latella describe a fatty tasting particulated whey protein in U.S. Pat. No. 4,734,287. Similarly, in European Pat. App. No. 323,529, they describe macrocolloids derived from plant, microbial and other animal sources, and in WO 89/05587, Singer along with Chang, Dunn, and Hatchwell, disclose a particulated complex having casein cores with shells of egg white protein. In U.S. Pat. No. 4,855,156, Singer, Wilcox and Podolski, prepare frozen desserts with these materials. And, in U.S. Pat. No. 4,911,946, Singer, Chang, Tang and Dunn, disclose a carbohydrate cream substitute which comprises macro-colloidal particles of suitable carbohydrates. In each of these cases, the particle sizes are maintained under about two microns, and the products are too heat sensitive to be of use in many food applications. It would be advantageous to have a fat mimetic which had enhanced heat stability, and to preferably withstand the rigors of normal food heating processes.
It would be desirable to have a selection of yet further fat mimetic materials which could be used to impart nutritional and functional properties to foods and to the diet.